The BoxWave Keyboard Buddy is the latest physical keypad case for the iPhone 4. Like the ThinkGeek version featured before it, this accessory is physically connected to the smartphone but still requires a Bluetooth connection to work. However, unlike ThinkGeek's TK-421, the keypad slides rather than swivels out. This makes it look a little like the Motorola Milestone.
At $70, it's pricier than the TK-421. The good news for the international crowd is that BoxWave ships to a lot more countries than ThinkGeek, so you may actually be able to get your hands on one without using complicated forwarding services. It's currently on preorder and will ship on December 14.